The present invention relates to surgical instruments, such as forceps, which are used in surgery and medical procedures. More particularly, the present invention pertains to the structure of a remotely actuated treatment device, which is located at the distal end of an insert member.
FIGS. 7(a) and 7(b) show a typical prior art surgical instrument. The instrument has a pair of cup-shaped cutting jaws 7 and 8 that are rotatably supported by a fixed center shaft 9. The instrument also includes a link mechanism 10 that opens and closes the jaws 7, 8. The link mechanism 10 is remotely manipulated by an operational wire 11. The closing motion of the jaws 7, 8 removes body tissue when the device is appropriately positioned within a human or animal body.
The link mechanism 10 includes actuating levers 12, 13 extending from the jaws 7, 8, respectively. Actuating links 26 and 27 are rotatably coupled to the levers 12, 13 by actuating shafts 28, 29. The links 26 and 27 are rotatably supported on the distal end 11a of the operational wire 11 by a movable center shaft 30.
The link mechanism 10 includes the actuating levers 12, 13, or rigid links, and the actuating links 26, 27. The levers 12, 13 and the links 26, 27 are pivotally coupled by the fixed shaft 9, the actuating shafts 28, 29 and the movable shaft 30. When assembling the mechanism 10, the holes in the links 26, 27 have to be aligned with the holes in the levers 12, 13 and with the hole in the distal end 11a of the operational wire 11 such that the shafts 28, 29 and 30 can be inserted in the aligned holes. The assembly of the mechanism 10 is therefore troublesome.